This invention relates, in general, to movement sensors detecting pressure, temperature, and acceleration, such as accelerometers, and more specifically, to mechanical sensors using semiconductor material.
Conventional sensors designed for measuring or detecting forces due to pressure, temperature, or acceleration, such as accelerometers, frequently incorporate deflectable diaphragms or cantilevered beams with contact points along the axis of deflection. As a force is applied to the deflectable member, the contact points are deflected towards stationary points situated opposite and adjacent to the contact points where they make physical contact. As the points contact, an electric signal is fed through the two points and into an electronic circuit. As the deflectable member is deflected farther due to additional forces, other contacts located along the member physically contact opposite stationary points, and supply similar signals to the electronic circuit. The circuit can then evaluate the signals received through these physical contacts to determine how far the deflectable member deflected. This allows the circuit to determine the forces applied to the sensor.
Modern sensors are frequently miniaturized and require micromachining. Due to the small size of the micromachined sensors, the contact points are very susceptible to corrosion and buildup which effects the performance of the sensor.